Casey is completing an experiment that requires a 300 ml solution with a 20% concentration of potassium chloride (kcl). but casey's lab only stores potassium chloride at concentrations of 10% and 50%. how much 10% kcl solution will casey have to mix with 50% kcl solution to make 300 ml of 20% kcl solution?

Lian is deciding which of two gyms to join. each gym charges a monthly rate plus a one-time membership fee. lian correctly wrote and solved a system of linear equations by substitution to compare the costs of the memberships. in her work, she substituted an expression for one variable and solved for the other. this resulted in the equation 75 = 75. what can lian conclude? one gym charges $75 per month. each gym charges $75 per month both gyms charge the same monthly rate and the same membership fee. both gyms charge the same monthly rate, but not the same membership fee.